The present disclosure relates to additive manufacturing and, more particularly, to removing conglomerated powder from within an internal passage.
Precision engineered parts such as gas turbine components may be manufactured by an additive manufacturing operation such that features associated with conventional manufacturing processes, e.g., machining, forging, welding, casting, etc. can be eliminated to facilitate savings in cost, material, and time. Additive manufacturing often results in conglomerated powder building-up around, and within, the completed component as an artifact of the process. When additive manufacturing a component that has internal passages, this conglomerated powder often becomes entrapped in the internal passages and is difficult to remove.
There are currently few methods that directly and rapidly remove the conglomerated powder. One standard practice may include repeated use of an accelerated media blast, combined with mechanically scraping. Another standard practice includes, mega sonic or ultrasonic vibratory methods to liberate the powder particles. Oftentimes, such practices are still inefficient at removal of removing conglomerated powder from within the internal passages.
Additively manufactured passages have a non-uniform roughness that varies both circumferentially as well as axially. The circumferential variation is a direct effect of layering nature of both a deposition and powder bed processes. The finish is finest on the bottom and progressively deteriorates towards the roof of the passage on horizontal passages with respect to the layered deposition process, while vertical passages will have a relatively uniform finish. In addition, the Electron Beam Melting additive process partially sinters material in the formed passage making powder removal difficult in such passages.